1. Field of the Invention
The present invention relates to a recording apparatus and a recording method for recording an image on a recording medium.
2. Description of the Related Art
When an image is to be recorded on continuous paper, which is pulled out from roll paper (rolled continuous paper), with a full-line type ink jet recording apparatus, it is ideal that the conveyance direction of the continuous paper is perpendicular to the longitudinal direction of a recording head. However, the conveyance direction of the continuous paper may not constantly be perpendicular to the longitudinal direction of the recording head, so that the continuous paper may possibly skew. If the continuous paper skews, the position of an image to be recorded thereon shifts with respect to the continuous paper, and the image cannot be recorded at an exact position thereon. For example, when an L-size (89×127 mm) image is to be recorded as a bordered photograph with 4-mm margins on continuous paper, there may be a case where a margin width at one side end is 2 mm and a margin width at the other side end is 6 mm in the continuous paper conveyance direction. When the continuous paper is trimmed into the L size in this state, uneven margin widths at both ends and at the top and bottom may arise and an undesirable photograph may be produced.
Japanese Patent Application Laid-Open No. 5-142914 discusses a technique for preventing color misregistration by detecting a side end position of a recording sheet with a detection unit and, based on the detected side end position information, shifting an image according to a skew state of the recording sheet. While Japanese Patent Application Laid-Open No. 5-142914 discusses an image recording apparatus for repetitively overlaying images of a plurality of colors onto the same recording region on the recording paper for each color to form a color image, this configuration can be achieved with continuous paper conveyance in a full-line type ink jet recording apparatus. Specifically, the adjustment of margin positions can be attained by detecting a side end position of the continuous paper with a detection unit provided at a side end of the conveyance path and shifting the position of an image according to the skew state of the continuous paper based on the detected information.
However, full-line type ink jet recording apparatuses perform various corrections in addition to continuous paper skew correction. For example, a full-line type ink jet recording apparatus performs head shading correction to correct a variation in amount of discharge by discharge nozzles. A full-line type ink jet recording apparatus having full-line type ink jet recording heads with a plurality of nozzle chips performs inter-chip registration adjustment correction and non-discharge complementary correction for complementing non-discharge nozzles. Basically, the full-line type ink jet recording apparatus performs these corrections on a nozzle basis. Therefore, when skew correction is performed with the image shifting discussed in Japanese Patent Application Laid-Open No. 5-142914, it is necessary to take into consideration interactions with such a plurality of corrections. Generally in head shading correction, the image density is adjusted to a dense level for nozzles having a small amount of discharge and to a light level for nozzles having a large amount of discharge. Therefore, since the processing of shifting an image affects head shading correction, the image shift processing needs to be performed prior to the head shading correction processing. Further, in registration adjustment correction, in a case where adjacent nozzle chips are overlapped, it is common to perform processing for smoothly connecting between nozzle chips by gradually changing the number of nozzle chips used in an overlapped region. Therefore, the image shift processing also needs to be performed prior to the registration adjustment correction processing. This also applies to the non-discharge complementary correction processing. Specifically, shifting an image after determining the non-discharge nozzle processing will result in incomplete non-discharge nozzle processing. Therefore, the image shift processing needs to be performed prior to the non-discharge complementary correction processing. This means that the image shift processing needs to be performed prior to various processing operations.
In image shift processing, the detection unit provided at a side end of the conveyance path detects a side end position of the continuous paper to determine the amount of image shifting. This processing needs to be made prior to various image processing operations including the head shading correction processing, the inter-chip registration adjustment correction, and the binarization processing for determining discharge and non-discharge including correction processing such as non-discharge complementary correction. Thus, a plurality of pieces of processing needs to be performed between a timing of detecting a side end position of the continuous paper and a timing of recording. Therefore, if the plurality of pieces of processing is performed after the image shift processing, skew correction control may not in time.